jp.ac.tokushima_u.is.ll.io.LanguageJsonHandler.java Source code

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Here is the source code for jp.ac.tokushima_u.is.ll.io.LanguageJsonHandler.java

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/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package jp.ac.tokushima_u.is.ll.io;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.mime.MultipartEntity;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONArray;
import org.json.JSONObject;
import org.xmlpull.v1.XmlPullParser;

import android.content.ContentProviderOperation;
import android.content.ContentResolver;
import android.database.Cursor;
import android.net.Uri;
import android.util.Log;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.Map;

import jp.ac.tokushima_u.is.ll.provider.LearningLogContract;
import jp.ac.tokushima_u.is.ll.provider.LearningLogContract.Languages;
import jp.ac.tokushima_u.is.ll.provider.LearningLogContract.SyncColumns;
import jp.ac.tokushima_u.is.ll.util.ApiConstants;
import jp.ac.tokushima_u.is.ll.util.HttpClientFactory;
import jp.ac.tokushima_u.is.ll.util.Lists;

/**
 * Handle a remote {@link XmlPullParser} that defines a set of {@link Sessions}
 * entries. Assumes that the remote source is a Google Spreadsheet.
 */
public class LanguageJsonHandler extends JsonHandler {
    private static final String TAG = "LanguageJsonHandler";
    private String systemUrl = ApiConstants.system_url;
    private String syncServiceUrl = "/sync";
    private String languageSearchUrl = "/language.json";

    public LanguageJsonHandler() {
        super(LearningLogContract.CONTENT_AUTHORITY);
    }

    public ArrayList<ContentProviderOperation> parse(ContentResolver resolver) {
        final ArrayList<ContentProviderOperation> batch = Lists.newArrayList();

        Uri uri = Languages.CONTENT_URI;
        String sortOrder = SyncColumns.UPDATED + " desc";
        Cursor cursor = resolver.query(uri, LanguagesQuery.PROJECTION, null, null, sortOrder);
        try {
            if (cursor.moveToFirst()) {
                Log.d(TAG, "Language has been inserted");
                int count = cursor.getCount();
                if (count > 3) {
                    return batch;
                }
            }
        } finally {
            cursor.close();
        }

        HttpPost httpPost = new HttpPost(this.systemUrl + this.syncServiceUrl + this.languageSearchUrl);
        try {
            DefaultHttpClient client = HttpClientFactory.createHttpClient();
            MultipartEntity params = new MultipartEntity();
            httpPost.setEntity(params);
            HttpResponse response = client.execute(httpPost);
            HttpEntity entity = response.getEntity();
            if (entity != null) {
                InputStream instream = entity.getContent();
                String result = convertStreamToString(instream);
                instream.close();
                JSONObject json = new JSONObject(result);
                if (json != null) {
                    JSONArray array = json.getJSONArray("languages");
                    if (array != null) {
                        for (int i = 0; i < array.length(); i++) {
                            JSONObject o = array.getJSONObject(i);
                            String languageId = o.getString("id");
                            if (languageId == null || languageId.length() <= 0)
                                continue;

                            ContentProviderOperation.Builder builder = ContentProviderOperation
                                    .newInsert(Languages.CONTENT_URI);

                            builder.withValue(Languages.LANGUAGE_ID, languageId);
                            if (o.getString("code") != null && o.getString("code").length() > 0
                                    && !"null".equals(o.getString("code")))
                                builder.withValue(Languages.CODE, o.getString("code"));
                            if (o.getString("name") != null && o.getString("name").length() > 0
                                    && !"null".equals(o.getString("name")))
                                builder.withValue(Languages.NAME, o.getString("name"));
                            builder.withValue(SyncColumns.UPDATED, Calendar.getInstance().getTimeInMillis());
                            batch.add(builder.build());
                        }
                    }
                }
            }
        } catch (Exception e) {
            Log.d(TAG, "exception occured", e);
        }

        return batch;
    }

    private static String convertStreamToString(InputStream is) throws UnsupportedEncodingException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is, "utf-8"));
        StringBuilder sb = new StringBuilder();

        String line = null;
        try {
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                is.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return sb.toString();
    }

    private interface LanguagesQuery {
        String[] PROJECTION = { Languages.LANGUAGE_ID, Languages.CODE, Languages.NAME, SyncColumns.UPDATED };

        int LANGUAGE_ID = 0;
        int CODE = 1;
        int NAME = 2;
        int UPDATEd = 3;
    }
}